The multi-faceted synergy between Swift and Fermi in radio-loud AGN studies

TL;DR

This paper discusses how the combined observations of Swift and Fermi telescopes have advanced understanding of gamma-ray emitting AGN by analyzing variability, spectral energy distributions, and source associations over six years.

Contribution

It highlights the novel synergy between Swift and Fermi in studying radio-loud AGN, enabling detailed multi-frequency analysis and improved source identification.

Findings

Correlated variability observed across optical to gamma-ray bands.

Time-resolved spectral energy distributions constrain emission mechanisms.

Swift follow-ups confirmed associations of gamma-ray sources with low-energy counterparts.

Abstract

Since its launch in 2008 June, the Fermi Gamma-ray Space Telescope has opened a new era in high-energy astrophysics. The unprecedented sensitivity, angular resolution and effective area of the Large Area Telescope on board Fermi, together with the nearly continuous observation of the entire gamma-ray sky assures a formidable opportunity to study in detail gamma-ray emitting AGN of various types. In this context the Swift satellite, thanks to its broad band coverage and scheduling flexibility, creates a perfect synergy with Fermi. Swift and Fermi coordinated monitoring campaigns of radio-loud AGN allowed us to investigate correlated variability at different frequencies and to build time-resolved spectral energy distributions from optical to gamma-rays, constraining the emission mechanisms at work in these objects. The rapid Swift follow-up observations of gamma-ray flaring AGN detected by Fermi-LAT were also fundamental in firmly associating the gamma-ray sources with their low-energy counterparts. We present some interesting results obtained from Fermi-LAT and Swift observations of gamma-ray flaring AGN in the first six years of Fermi operation.